From the perspective of differential cylinder, the differential connections of hydraulic motor were studied, and a differential connection method was put forward. Through the analysis of the differential connections of different-acting double-stator motors, the mathematical expressions of the motor’s rotational speed and torque were obtained. As for the effect of motor displacement scale factor C on the differential connection, the values of C for the single-acting, double-acting and multi-acting double-stator motor were found out respectively. These can make the motor differential connections turn out the same results or even fail to work. The number of repeated groups and failure points was calculated. This work will offer a new way for the theoretical research of hydraulic motor differential connection. 